Maximum

Typical

Load at rated power: 1000 hours at 70°C

∆R%

5

1

Shelf life: 12 months at room temperature

∆R%

3

0.5

Derating from rated power at 70°C

Zero at 155°C

Dry heat: 1000 hours at 155°C

∆R%

2.5

1

Climatic category

55 / 155 / 56

Long term damp heat

∆R%

3

1

Temperature rapid change

∆R%

2

0.5

Resistance to solder heat

∆R%

2

0.5

Voltage proof

volts

500

Surface Mounted

Thermistors

PTCR Series

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Issue C · 08.04

Welwyn Components

38

Performance Data

Operating Temperature Range

The chips themselves can operate at a maximum

temperature of 155°C (see performance claims above). For

soldered chips, the joint temperature should not exceed

110°C. This condition is met when the stated power levels

at 70°C are used.

Mounting

This chips resistor is ideally suited for handling by

automatic methods due to its rectangular shape and small

dimensional tolerances. Electrical connection to a ceramic

substrate or to a printed circuit board can be made by flow

or reflow soldering of wraparound terminations. The

terminations provide good ‘leach’ properties and ensure

reliable contact. Due to the robust construction the resistor

chip can be immersed in a solder bath for 10 seconds at

260°C. This enables the resistor to be mounted on one

side of a printed circuit board and wire-leaded components

on the other side.

Construction

Thick film resistor material, overglaze and organic protection

are screen printed on a 96% alumina substrate.

Terminations

Wrap-around terminations are suitable for soldering.

Solderability

Wrap-around terminations have an electroplated nickel barrier

and solder coating. This ensures excellent leach resistance

properties and solderability. They will withstand immersion in

solder at 260°C for 10 seconds.

Marking

All relevant information recorded on the primary package or

reel.

Solvent Resistance

The chips are resistant to all normal industrial cleaning fluids

suitable for printed circuits.

Packing

As standard 3000 chips are supplied taped and reeled on

8mm tape to IEC 286-3.

Application Notes

Type

1206

400R

G

Resistance value

(IEC62 code)

Tolerance

(IEC62 code)

Specify type reference, value and tolerance as shown in

this example of PTCR1206 400R 2%:

Ordering Procedure

F1%

G2%

J5%

PTCR_C.qxd

8/9/04

4:00 PM

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